The features, aspects and embodiments disclosed herein relate to the manufacture of devices in which one material layer is to be coupled to another layer, such as in device packaging applications, yielding improved methods and apparatus.
Wafer bonding techniques have been employed to create seals for semiconductor packaging systems for decades. Some known wafer bonding techniques may include an intermediate layer between two material layers, and may be characterized as employing organic adhesive bonding, such as UV curable organic epoxy glue. While this bonding technique has been described in the art as providing a hermetic seal, in practice the degree of hermeticity varies among the techniques and as a function of the environment to which the seal is exposed. The results are unsatisfactory for certain applications, especially long term moisture exposure.
It has been discovered that a screen printing process may be employed to apply a glass and/or ceramic frit paste or a metal solder paste to one or more surfaces of a layered material structure, followed by heating steps to bond one or more of the layers together to achieve a hermetic seal.